I agree with backporting Netty 4 and the related patches to 3.5.5. +1 (non binding) (and I might have already voted)
If it took so long to release a stable 3.5, I don't think we should leave a known bug in the system, which has such an impact (not supporting current LTS java). The PRs shouldn't be hard to backport, no new development is required, and unfortunately maven migration isn't finished yet, so it's not like we need to postpone the release just because of Netty upgrade. That's my two cents anyway. Regards, Norbert On Wed, Jan 9, 2019 at 9:19 PM Enrico Olivelli <eolive...@gmail.com> wrote: > Il giorno mer 9 gen 2019 alle ore 21:16 Andor Molnar > <an...@apache.org> ha scritto: > > > > So, you guys saying we should upgrade to Netty 4 and backport the > following patches too: > > > > ZOOKEEPER-3131 org.apache.zookeeper.server.WatchManager resource leak > > ZOOKEEPER-3163 Use session map to improve the performance when closing > session in Netty > > ZOOKEEPER-3146 Limit the maximum client connections per IP in > NettyServerCnxnFactory > > ZOOKEEPER-3177 Refactor request throttle logic in NIO and Netty to keep > the same behavior and make the code easier to maintain > > > > I think it’s still deliverable with the stable release. Regarding the > timing, let’s say we release 3.5.5 with Netty 3 and do the upgrade in > 3.5.6. Is it acceptable to do such a big with a minor version change? > > I think we can do the upgrade in 3.5.5. > We can't say Java 11 is supported if we don't have tests working. And > Java 11 is the current LTS release from Oracle. > > If we release now 3.5.5 then we need to work for 3.5.6 and then > release....it is a double work, we don't have so much resources :-( > > IMHO it is better to release 3.5.5 and start focusing on 3.6.0 > > Enrico > > > > > Upgrading now isn't ideal either, but maybe somewhat less brutal. > > > > Regards, > > Andor > > > > > > > > > > > On 2019. Jan 8., at 2:10, Brian Nixon <brian.nixon...@gmail.com> > wrote: > > > > > > Also worth consideration for the Netty fixes backport bundle: > > > > > > ZOOKEEPER-3131 org.apache.zookeeper.server.WatchManager resource leak > > > > > > Our experience with Netty has been positive so far though I don't > think we > > > have enough info to declare it is stable. It makes a lot of sense to > me for > > > 3.5 to use Netty 4, the biggest question is the timing. > > > > > > > > > On Fri, Jan 4, 2019 at 10:44 AM Andor Molnár <an...@apache.org> wrote: > > > > > >> I got another one: > > >> > > >> ZOOKEEPER-3163 Use session map to improve the performance when closing > > >> session in Netty > > >> > > >> > > >> So, that doesn't seem too many. We can talk about backporting them, > but > > >> I don't think they're super critical for the first stable release. > > >> > > >> Regarding 3.4, I need to validate the embedded scenario, but at least > > >> the Java 11 build is green. :) > > >> > > >> > > >> Andor > > >> > > >> > > >> > > >> On 1/4/19 18:08, Enrico Olivelli wrote: > > >>> Il giorno ven 4 gen 2019 alle ore 17:04 Norbert Kalmar > > >>> <nkal...@cloudera.com.invalid> ha scritto: > > >>>> +1 for Netty 4 in 3.5 > > >>>> > > >>>> Pretty much all the pros and cons has been said before me. > > >>>> I would only add that this is not a new functionality that we wan't > to > > >>>> backport. It's a criticall(ish?) bugfix, which requires quite a bit > of > > >>>> change unfortunately. > > >>>> > > >>>> Regards, > > >>>> Norbert > > >>>> > > >>>> On Fri, Jan 4, 2019 at 4:36 PM Andor Molnar <an...@apache.org> > wrote: > > >>>> > > >>>>> What are those patches exactly? > > >>>>> > > >>>>> Comparing the ported version of 3.5 with master I’ve only found 2 > > >> patches > > >>>>> which are missing: > > >>>>> > > >>>>> ZOOKEEPER-3146 Limit the maximum client connections per IP in > > >>>>> NettyServerCnxnFactory > > >>>>> ZOOKEEPER-3177 Refactor request throttle logic in NIO and Netty to > keep > > >>>>> the same behavior and make the code easier to maintain > > >>>>> > > >>>>> None of them are critical I would say. > > >>>>> Is there anything else I’m missing? > > >>> I have compared the histories and I think Andor you are right. > > >>> > > >>> master: > > >>> https://github.com/apache/zookeeper/commits/master > > >>> > > >>> branch-3.5: > > >>> https://github.com/apache/zookeeper/commits/branch-3.5 > > >>> > > >>> Sorry I was thinking to the amount of patches related to TLS stuff , > > >>> but they are not related to Netty 4. > > >>> > > >>> What about branch 3.4 ? > > >>> We don't have reconfig but the case "Start embedded ZK, stop it and > > >>> try to restart on the same port" should apply as well. > > >>> > > >>> Enrico > > >>> > > >>>>> Andor > > >>>>> > > >>>>> > > >>>>> > > >>>>> > > >>>>>> On 2019. Jan 4., at 16:27, Enrico Olivelli <eolive...@gmail.com> > > >> wrote: > > >>>>>> > > >>>>>> Il giorno ven 4 gen 2019 alle ore 14:23 Andor Molnar > > >>>>>> <an...@apache.org <mailto:an...@apache.org>> ha scritto: > > >>>>>>> Hi team / Enrico, > > >>>>>>> > > >>>>>>> I’d like to get feedback from the community on the following > patch > > >>>>> (moving the discussion from GitHub to here): > > >>>>>>> https://issues.apache.org/jira/browse/ZOOKEEPER-3204 < > > >>>>> https://issues.apache.org/jira/browse/ZOOKEEPER-3204> > > >>>>>>> https://github.com/apache/zookeeper/pull/753 < > > >>>>> https://github.com/apache/zookeeper/pull/753> > > >>>>>>> In a nutshell: looks like that Netty 3.10 is broken under Java > 11: it > > >>>>> doesn’t properly close the underlying socket (probably not closing > the > > >>>>> registered NIO selectors) and reconfig tests are unable to re-bind > the > > >>>>> ports. This problem is similar that we already fixed in NIO with > the > > >>>>> following patch: > > >>>>> > > >> > https://github.com/apache/zookeeper/commit/c3babb94275ad667dc71c10dcb08a383a3c154c2 > > >>>>> < > > >>>>> > > >> > https://github.com/apache/zookeeper/commit/c3babb94275ad667dc71c10dcb08a383a3c154c2 > > >>>>>>> The problem doesn’t show up on trunk which has been recently > upgraded > > >>>>> to Netty 4. > > >>>>>>> Repro: > > >>>>>>> - Start embedded ZK, stop it and try to restart on the same > port, or > > >>>>>>> - Start normal ensemble and reconfig to use different (client) > port. > > >>>>> Then reconfig back to the original port which should fail. (that’s > the > > >>>>> scenario which is covered in ReconfigTest) > > >>>>>>> I created the above patch (#753) to backport Netty 4 upgrade to > 3.5 > > >> and > > >>>>> it fixes the problem with Java 11 (it doesn’t cause regression in > the > > >>>>> pre-commit build either), but Enrico is having concerns about > making > > >> such > > >>>>> big change before the release. > > >>>>>>> I tend to agree, but let’s see what are the options. > > >>>>>>> > > >>>>>>> Thoughts: > > >>>>>>> - Do we have to fix this? - Yes. Java 11 is LTS and I the bug is > > >>>>> critical. > > >>>>>>> - Can we fix Netty 3? - Maybe. Let’s say we find the bug in > Netty 3, > > >>>>> what can we do? > > >>>>>>> a) We cannot workaround from ZooKeeper itself and have to > > >> submit > > >>>>> a pull request for Netty. I think it’s quite unlikely that they > will > > >> accept > > >>>>> the change given it’s not a security bug, but even if they did, > only > > >> the > > >>>>> upgraded version of Netty 3 would work properly with ZooKeeper. > Err. > > >>>>>>> b) We can workaround it from ZooKeeper: that could be option > > >> #1, > > >>>>> but I have a strong feeling about it’s not going to be the case. > > >>>>>>> - Shall we upgrade to Netty 4? - this is option #2 > > >>>>>>> > > >>>>>>> Please share your thoughts, maybe you know about an option #3. > > >>>>>> Thank you Andor > > >>>>>> > > >>>>>> I have thought more about this problem, and I have checked that > Netty > > >>>>>> 3 is really dead/unmantained (last release in 2016). > > >>>>>> If I understand correctly there is no easy workaround (nothing > without > > >>>>>> hacking Netty 3 internals) > > >>>>>> > > >>>>>> As soon as we will declare 3.5.5 "stable" the world will hopefully > > >>>>>> abandon 3.4 and switch to 3.5 + Netty (because of SSL support). > > >>>>>> The network stack is very important so it is better to have Netty > 4 as > > >>>>>> foundation, I am thinking about security issues, we won't make an > > >>>>>> "hotfix" release with the switch to Netty 4 because there is a > bad bug > > >>>>>> in Netty 3. > > >>>>>> So better to switch now. > > >>>>>> > > >>>>>> But Facebooks friends, expecially @ivmaykov did a lot of bugfixes > > >>>>>> around Netty on master branch, we must be sure that what we are > > >>>>>> delivering in 3.5.5 is stable. > > >>>>>> > > >>>>>> We will also have to state clearly in the "release notes" that > Netty > > >>>>>> version is changed, as this may have a non trivial impact to > memory > > >>>>>> usage (i.e. Netty 4 uses more Direct memory by default) > > >>>>>> > > >>>>>> So to recap my final opinion: +1 to switch to Netty 4 if we take > care > > >>>>>> of port all of the fixes around Netty 4 from master branch and we > > >>>>>> state the switch clearly in the release notes > > >>>>>> > > >>>>>> Enrico > > >>>>>> > > >>>>>>> Regards, > > >>>>>>> Andor > > >>>>> > > >> > > >
